Specific minerals are known to stimulate plant growth in agriculture. For example, fertilizers and other additives can contain silicon compounds, such as, calcium silicate, magnesium silicate, potassium silicate, and sodium silicate. Fertilizers and the other additives can deliver these minerals, these compounds, or combinations of these minerals and these compounds to a plant or to soil. The method of delivering the minerals or compounds, the crystal structure of the minerals or compounds, and the combination of the minerals or compounds impacts the efficacy of the fertilizers and other additives, for example, by impacting the solubility of them. Soluble compounds are able to travel through soil, plants, and/or portions of plants (such as a cell wall) better than insoluble compounds.
The minerals or compounds in the fertilizers or other additives are produced in several forms. For example, the minerals or compounds in the fertilizers or other additives can be natural (for example, mined) or synthetic (for example, a by-product of an industrial process). Utilizing synthetic minerals or compounds, such as, by-products, can be environmentally beneficial by reducing waste and economically beneficial by creating economic value to existing waste.
One such by-product is slag. Slag is generally perceived as a waste material. However, most slag can be used in road surfaces, roofing, or cementitious products. The source of slag impacts the composition of the slag and, thus, the end-use of the slag or portions of the slag. For example, blast furnace slag is known to be used in roads and cementitious products; however, it has previously been perceived as undesirable for agricultural products due to its composition. Stainless steel slag (greater than 10.5 weight % Chromium is indicative of a stainless steel product) has been used for roads and cementitious products as well as agricultural products due to its compositions. However, stainless steel slag can be limited in availability.
Additionally or alternatively, making of agricultural blends from slag sources, especially pelletized agricultural blends, can involve difficulty in dispersion during blending, pellet strength, and combinations thereof.
Applying such agricultural blends can also be difficult. Silicon from different sources, such as different composition slags, can have a different structure. In addition, silicon can have different structures based upon process parameters, such as, the cooling rate of the slag, and/or based upon physical characteristics, such as granular size of the compound. These different structures can affect solubility of compounds containing silicon. Solubility impacts the ability for silicon to be processed by plants and/or the ability to sequester heavy metals. Thus, information about silicon that fails to identify whether the silicon is in a soluble compound can be misleading or unreliable by failing to properly identify the impact of including such silicon. In addition, lacking such information prevents proper identification of preferred minimum ranges of silicon from soluble compounds.
What is needed is a method of treating soil and a method of sequestering heavy metals, where the methods apply an adequate amount of silicon from soluble compounds.